Phthalocyanine is a compound which, in its center, can coordinate to a metal, expresses a blue to green color, and exhibits various optical characteristics (e.g., selective absorption of visible light of 600 nm to 700 nm). Therefore, phthalocyanine is envisaged to be applied in a variety of fields, including light-emitting materials, fluorescent materials, and photodynamic therapeutic drugs for cancer, and many derivatives of phthalocyanine have been synthesized (Non-Patent Documents 1 and 2).
Meanwhile, a dendrimer is a dendritic molecule having a branching structure formed of repeating units. When a dendrimer is bonded to a compound serving as a core, the entire molecule assumes a spherical form. Dendrimers are envisaged to be used as, for example, optoelectronic materials, by virtue of their characteristics such as solubility, low viscosity, and amorphousness (Non-Patent Documents 3 and 4).
As has been reported, a phthalocyanine derivative serving as a photosensitizer can be used as a core of a dendrimer (Patent Document 1). However, since this phthalocyanine dendrimer has an aromatic ether dendron unit, the entire dendrimer molecule assumes a spherical form and loses intrinsic optical characteristics acquired by a phthalocyanine structure.    Patent Document 1: JP-A-2005-120068    Non-Patent Document 1: Ryo Hirohashi, Keiichi Sakamoto, and Eiko Okumura “Phthalocyanine as a Functional Dye” IPC, 2004    Non-Patent Document 2: Hirofusa Shirai and Nagao Kobayashi “Phthalocyanine—Chemistry and Function—” IPC, 1997    Non-Patent Document 3: Keigo Aoi and Masaaki Kakimoto “Dendritic Polymers, Tabunki Kozo ga Hirogeru Kokinoka no Sekai (World of High Functionalization Diversified by Multibranched Structures)” NTS, 2005    Non-Patent Document 4: Shohiko Okada “Chemistry and Function of Dendrimers” IPC, 2000